The present invention relates to a method and apparatus for automatically cleaning a swimming pool.
U.S. Pat. No. 5,985,156 describes apparatus including a unitary body having (1) a level control subsystem for selectively moving the body to a position either proximate to the surface of a water pool or proximate to the interior surface of a wall containing the water pool, (2) a propulsion subsystem operable to selectively propel the body in either a forward or rearward direction, and (3) a cleaning subsystem operable in either a water surface cleaning mode (e.g., skimming or scooping) or a wall surface cleaning mode (e.g., vacuuming or sweeping). The patent discloses that these subsystems can be powered by hydraulic, pneumatic, and electric power sources and specifically describes hydraulic embodiments powered by positive and negative water pressure.
Applicant""s parent application Ser. No. 09/440109, now U.S. Pat. No. 6/294,084.(which is incorporated herein by reference) and this CIP application describe embodiments in which one or more of the aforementioned subsystems is powered by an electric source such as solar cells and/or rechargeable batteries and/or a wire extending to the unitary body from an external (e.g., deck mounted) power source. The batteries can be charged from solar cells carried by the unitary body or via an appropriately configured docking station. The described embodiments can use either a heavier-than-water body or a lighter-than-water body. When a heavier-than-water body is used, the body in its quiescent or rest state typically sinks to a position proximate to the bottom portion of the containment wall. In an active state, the level control subsystem produces a vertical force component for lifting the body to proximate to the water surface. When a lighter-than-water body is used, the body in its quiescent state floats at a position proximate to the water surface. In an active state, the level control subsystem produces a vertical force component for causing the body to descend to proximate the wall bottom portion.
The present CIP application introduces a further system embodiment which uses separate top and bottom units tethered together by a conduit in lieu of the unitary body heretofore described. The top unit functions to clean the water surface in a manner analogous to the unitary body when operating in the water surface mode and the bottom unit functions to clean the wall surface in a manner analogous to the unitary body when operating in the wall surface mode.
In accordance with the invention, at least one of the tethered top and bottom units includes a propulsion subsystem powered by an electric source such as solar cells and/or rechargeable batteries and/or a wire extending from an external power source.
In a preferred tethered units embodiment, the top unit includes a solar cell for charging an on-board battery. The battery powers a flow generator, e.g., a motor driven propeller, which produces a water flow for propulsion and water surface cleaning. The top unit preferably supplies electric power and/or control signals via the conduit to the bottom unit for powering a flow generator for propulsion and wall surface cleaning. The top and/or bottom units preferably include containers for collecting debris.
The conduit additionally functions to physically transfer forces between the top and bottom units so that the unit being propelled can pull the other unit along. In a preferred embodiment, the units are oppositely oriented so, for example, forward propulsion of the top unit pulls the bottom unit rearwardly. Similarly, forward propulsion of the bottom unit pulls the top unit rearwardly. This preferred orientation enables the tethered pair to readily avoid getting trapped behind an obstruction in the pool.